Yes Data was clearly affected by the polywater intoxication.
As portrayed in the episode the intoxication seemed to spread by contact, and Data after a "fully functional" encounter with an infected Yar, shows clear signs of infection in his unusual behavior on the bridge and in his discussion with captain Picard.
While reinstalling the isolinear chips in engineering Data seemed to be enjoying it, and he actually was not interested until Wesley proposed it as a kind of game shuffling the chips like cards. It seems as if the polywater intoxication only affected judgement and behavior, but not ability, as Data was quite adept at quickly reinstalling the chips.
I think the most telling is that after Dr. Crusher perfected an antidote, Picard took a hypospray to engineering and Data was one of the first to be inoculated.
In general, after recently re-watching the first season, Data is initially treated as a much more biological artificial being, often shown in sick bay being examined and diagnosed by Dr. Crusher. So his being affected by the polywater is not out of character with the early treatment of Data in the TNG series.